Technical Erratic generator light

I have a 62 Thunderbird with a generator. I started noticing recently that it seems like my generator light was on all the time and would get dim a flicker when in idle. The other day it seemed like the starter was not turning the engine over as quickly as before when I would started it up in the morning. I looked on line and people were saying that at low idle the light might come on but turn off during normal driving. After reading that I noticed that it turned off when I was on the freeway but then the next day it stayed on while I was on the freeway. On Saturday I tried to start it up in the morning and the starter didn't have enough power to turn it over. The first thing I tried was getting a new belt. After I installed the belt I tried to stat the car and it fired right up. This was in the hot afternoon instead of the cold morning so that might have played a part. But the generator light was still on. At idle it is dim and flickering. When I revved it up a little the light brightened and stayed constant. My first thought is of coarse the generator but It seems pretty new and I don't want to just****ume that is the problem and by a new one. Any thoughts? I have not done a voltage test yet. Are there places that I can check the voltage in order to troubleshooting the problem? The voltage regulator looks new also but the little cylinder that is bolted to it looks old.

 

The little cylinder on the regulator is a capacitor, for noise reduction for the AM radio. It is not likely to cause any problems. But the voltage regulator itself could easily be the problem, even if it looks new. They don't make them like they used to.

First thing to do is get a volt meter and measure the voltage at the battery, with the engine off, then with it idling, then with it running at driving speed, but also note if the light is on at the time.

Then let us know, we might be able to help you figure it out...or not...

 

Ditto, get a voltmeter and see what the voltage is at the battery at idle and at about 1000 rpm. That will tell you what you need to do next.

 

I bet the brushes in the generator are sticking, or floating/warn out, and that's why the light gets brighter the faster the engine revs.

 

dirty contacts in the regulator will cause similar symptoms, too. And having a broken brush spring might be similar, but they usually make the light stay on all the time.

 

Easy test if the light is on at higher RPM and voltage is low is to apply battery 12V to the 'F' terminal on the generator. If the light goes out and voltage comes up, it's the regulator.

 

make sure and tell them about the 'other circuit'--for our ford fans

 

After I add AC my 56 Ford I changed to an Powermaster 100 Amp alternator which has a connection which can connects to the original “I-did-it”light. Has work perfect for 6 years.

 

Thanks I will do some testing over the weekend.

 

That was my thought. Worn out brushes in the generator and a commutator that needs cleaning up.

You should be able to sources brushes and bearings locally if you are willing to deal with the deer in the headlights look on the parts dude's face when you order them. You have to know exactly what generator the car has though.

 

https://forums.fordthunderbirdforum.com/threads/1962-generator-system-trouble.13252/
The internet has a lot of people that have had your same problem. a quick search found this.
The light is warning you that the charging system isn't operating properly. There are factory and other ways to check the system and determine the issue. Tossing parts at it is the expensive way that may not fix it.

 

I had the battery charged and tested this morning and everything checked out as far as the battery goes. I will test the voltage at the battery this weekend. I have an appointment with the mechanic to work on the alignment on Wednesday so I will ask them to test it while it’s there. If the generator is bad I might just use this as an opportunity to make the switch to an internally regulated alternator. I have one on my c10 and have been very satisfied.

 

What I recall from having a car with a generator and dash light, the light would turn on, mine said “gen” when you just turned the key on.
Once started and the generator was charging, the light would go off.

Now that could be a generator issue or regulator. Above was said how to test both.

 

On Fords, the idiot light is connected to the 'ACC' terminal on the ignition switch. If connected to the ignition terminal, the car would keep running as backfeed from the generator would supply power to the ignition.

 

So with everything connected as it is, I should run a wire from a completely different battery to the F terminal with the car running?

 

If the car is running another battery isn't needed.

 

Be careful when full fielding the generator. When you connect battery to the F terminal, the generator is no longer regulated and the voltage can go pretty high when you rev the engine. You should only do this with a voltmeter connected across the battery. That way you can watch the voltage to prevent any over-voltage damage.

 

just don't leave headlights on--otherwise no probs for normal testing time